The Viconics VT7600 (SE7600) LON thermostat does not display the nviSetpoint SNVT on its local display

[#1]

Issue

The Viconics VT7600 (or SE7600 - Schneider-Electric brand) LON thermostat displays a network variable input (nviSetpoint) with both the Niagara R2 and Niagara G3 stations. It is not available on the thermostat's local display.

Product Line

EcoStruxure Building Expert, TAC IA Series

Environment

• Viconics VT7600 SE7600
• Niagara R2
• Niagara G3

Cause

Add nviSetpoint to a Niagara-based graphic, but it cannot be cross-checked on the local display.  This may add confusion to the end users.

Resolution

nviSetpoint is, by design, a network variable without local display access.  It is used to calculate the occupied heating and occupied cooling setpoints (in conjunction with the deadband).  The occupied heating and occupied cooling setpoint have local display access.

Below is an excerpt from the Viconics LonWorks Integration Manual (page 😎 describing the function of nviSetpoint and how it works with deadband to create occupied heating and cooling setpoints:

Parameter	Variable Name	Function
Occupied Cool & Heat Setpoints	network Input SNVT_temp_p nviSetpoint	This input network variable is used to allow the occupied temperature setpoints only to be changed via the network from a single analog value. (Note: the Unoccupied setpoints are not changed.) The corresponding heating and cooling values are derived from the minimum deadband configuration value Default Null Value: 621.81°F (327.67°C or 0x7FFF) Ex. If the minimum deadband configuration value = 2°F and nviSetpoint = 70°F The resulting Occupied heating setpoint will equal 69°F which is derived from 70°F minus one half the minimum deadband configuration value of 2°F The resulting Occupied cooling setpoint will equal 71°F which is derived from 70°F plus one half the minimum deadband configuration value of 2°F